There seems to be some misunderstanding of how the Servo library and servos work.
Servo.write(angle) takes a value from 0 to 180. Usually a CR servo is stopped at roughly write(90), with 0 and 180 being full speed in opposite directions.
This program seems to spend a lot of time writing negative values to the servo. That's not going to do anything useful. It's pretty much impossible to send a negative length pulse to a servo and the Servo library won't even try.
Steve